System of radiogoniometry



I July'3l, 1928.

W. A. LOTH SYSTEM OF RADIOGONIOMETRY Filed April 14, 1924 Patented July 31, 1928.

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WILLIAM ARTHUR LOTHLOF. PARIS, FRANCE, ASSIGNOR rosocIErE INnUsrRInLLn nus rnocnnns w. A. LOTH, or PARIS, FRANCE.

SYSTEM or RADIOG'ONIOMETRY.

Application filed April 14, 1824, Serial No. 708,592, and in France April 23, 1923.

.A process and devices permitting the exact determination of the direction of magnetic and'electromagnetic fields of low, medium and high frequency. Thisinvention is characterized generally speaking, by the use of armatures permitting the determination of the lines of .force of the waves that pass through them with respect to a straight line situated at any distance from said armatures. This result is obtained by evaluating the maximum and minimum variations of the current of reception. These variations are determined in the case of variable lines of force by the displacements of brushes on a commutator electrically connected to the turns or elementary'windings of the armature, said armature remaining stationary. The variable position of these brushes deter-- mines the direction-relatively to a straight line in space of the lines of force or of the electromagnetic waves passing through the windings of the armature. The connnutators for collecting the current of the armatures may be so devised as to connect the turns arranged in parallel or in series, to a current receiver. The contacts on these commutators are eiiected by means of two brushes insulated from each other. It is obvious that the brushes could be more numerous and that the use of two brushes at 180 apart is only a particular example of the various possible manners of c ollecting the current produced in the turns of the corresponding armature by' thevariable magnetic or electromagnetic field.

The present invention relates to improvements in the construction of devices for collecting the currentsgenerated in the armatures by the variable magnetic or electromagnetic field; these improvements have more particularly for their object the-variation of the number of turns on the armatur'e without having to make gaps'or breaks between the turns constituting its winding.

In the accompanying drawing and by way of example; p p g 3 j, Figs. 1 and 2 illustrate in plan View two diiierent forms of construction of devices for collecting the current of the armatures, .made inaccordance with the improvements formingrthe subject-matter of the present invention.

In the form of construction shown-in Fig. 1 which shows the turns 2 of an armature woiuid' on a ring or on a drum, use is made of a fixed contact 78j and of a movable contact 4. This latter may be in the form, for instance, of a rider movable on a conducting rod 79-insulated from the turns of the armature and connected toa contact 80 by its end opposed to that ofthe fixed contact; This rider 4 rubs on the turns 2 of the armature so that a rheostat having a variable resistance and variable self inductance is thus obtained.

Supposing that a varying magnetic field of low frequency passes through the turns 2 having for instance at a given moment the direction indicated by the arrow 81. If the rider is in the position 84:, it will be'seen that the external circuit 82 carries a current the direction of which is given by the arrow 83. A. current will be produced which will pass through the following circuit: rider i, turns 2 comprised between the said rider at 84, and the point 78, conductor 82, amplifier 29, conductor 82, connection 80 and conducting circle 85. The value of this current will be maximum, as if the rider 4 is moved on either side of the point 84, it will be noted that'theintensity of this current diminishes.

If the rider is placed at point 85, arranged on a diameter at right angles to the direction of the arrow 81, two currents will be produced; a current circulating from point 85, towards point 78, and the other circulating from point 85 towards point 80. As the rider at point 85 divides thewinding ream 2 in two "equal parts, these. currents will'have arrow indicated at 83. It is a resultant of a the currents produced, on the one hand owing to the turns between 84 and 86 and, on theother hand, owing to the turns 84 and 78.

' If the field is set according to the arrow '88, it will be seen that for a position '89, of

the rider 4, symmetrical to 78, relatively to the direction 88, no current willl through th'e' circuit 82. I

,It'wil'l therefore be seen that by moving the rider 4: from the position illustrated on the drawing up to the point 84, a reception of increasing intensity will be obtained. It will be maximum when-the rider 4 will be at point 84. It will subsequently decrease, if

pass

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the rider i-iskept on mov'ingtor annulling it (minimum reception) when the latter reaches point'85. When the reception will be maximum, the' diameter passing through the'position occupied, at this moment, by the rider 4 on the conducting circle 89,,will give the direction of the magnetic field, that is to say the direction of the arrow 81.,

It is thus possible, with a fixed junction and even with a single' variable junction, to know the direct on of the various magnetic or electromagnetic fields.

In the same way, it is possibletomechanically alter the direction of the fixed junction '78. rela tively to the field the direction of whichis to. be determined. This can be effected by'rotation' of the conducting ring 79. This allows one to have for each direc tion a number of variable receiving turns.

Finally it is possible to use afixed junction and several variable junctions 'or several take on the armature a variable number of turns, the turns being separated from each other 'by breaks. As indicated hereafter it is also possible to take a. variable'number of;

turns and to group them in parallel or in series, at will, no break being made in, the

winding. 7 r

Fig. 2 illustrates, byway of example, a form of construction for'that purpose. 5 and 6' designate metallic brushes insulated from each other and placed at 180 5 and 6 designate a similar pair of brushes. 'These brushes can be arranged infthe same vertical plane. They do not theninclude any turnbetweenthem. As the angle 5, 0,5

and the'angle 6,0, 6 increase,the brushes "5 and 5" and 6 and 6 include between them an 1 increasing number of turns. The maxima of these angles reach 180; When a theylarereached, the brushes 5 and 6 on the one hand then arranged on' one and the same side of the armature relativley to O, as well-as the brushes 6 and 5', onthe other hand, are all in the same vertical plane. The turns included between'the brushes 5 and 5can be connected either in parallel .or in series with those included between the brushes 6 and 6,.by means of ai' simple switch. f Itis obvious that the angles 5, 0, 5'

and6, 0,6 maybe caused to vary, that is to say the group of turns placed between the brushes and 6 independently from each other. It suffices for this to render the brushes 5 and 6 on the one hand and the brushes 5- and 6' on'the otherhand', me- .chanic'ally independent from each other.

By turningthe milled head 90', the angles I 6, 0,6 and 5",10, 5 are caused to vary. This can be carried out whether the brushes 6 and 6' or-thelbrushes 5 and 5 move, according to equal angles, from the fictitious middle line .m-aa, whether theibrushes 5 or. 5', in

the first angle, or the brushes 6 or 6', in the second angle, arealone displaced, the other. side of the angle .remainingffixed. It] is, preferableto cause the two sides ofthe angle to move towards orfromthe middle line according to thesame extenti'or. one and the same rotation of the inilledhead 90.

Anothenmilled head might moreover be provided inorder to cause this'angle tovary more rapidly.

I so i The. milled head 91-permits the rotation ofthe whole of the four brushes according to any; angle for receiving. in the required direction. Another milled head may also be provided for a' rapidcrotation. noted that the turns which are not used do notpresent any'l'oose ends. It is. obvious It will be that: with these turns any requiredv combinations of circuits jean be effected, without in any way altering the principle of the reception. The, milled heads 90 acts to vary the receiving'turns between the brushes and I .91 acts to set these receiving turns in any direction. These can be operated either dilUO rectly by handor by' a clockwork which may be started at will. f These milled heads 90 and 91 can also beoperated at a, distance, being controlledjby one or more clock or electric motors .or the like, also controlled at a distance. i The milled heads 90 and 9l' orthe motors, are then provided with repeating devices whichv give at a distance the number of coils comprised... between the brushes or the angles made'by these brushes and theidirection ofthe bisector of. their angles, at the time of the/maximum or minimum of reception. This giving'by'jtheresd' nance the directions of the magnetic or elece tromagneticfields. I By add'nga pair of brushes to the preceding ones, it is possible to simultaneously and independently receive from another direction. i

All, the applications provided for the other arrangements of collector-sot currents on the armatures are applicable in these cases j V V These same arrangements may, moreover,

serve for radiation. By adding two other brushes, two radiations can be obtainedin two different directions. v 'Whether? at the,

reception or at radiation, it will be noted that. the tuning of the receiving circuit or emitting circuit is obtainedby" means ofa variable self induction coil (giving also a variable capacity) all the turns of which are receiving turns, that is to say active, instead of adding, as usually done, a nonreceiving variable self-induction coil which introduces in the circuit impedance and damping.

What I claim as my invention and desire to secure by Letters Patent is: i

1. In an electromagnetic direction finding device, a plurality of serially connected turns, means for short circuiting some of said turns, a current indicating device, means for connecting said current indicating device to the non-short circuited turns, said short circuiting means being included in the circuit of the indicating device;

2. In a system of radiogoniometry comprising an endless winding, the connection of one of the turns of the said winding with i one of the conductors of the radiogoniometry station, a conducting circle extending above the whole of the said turns, a gap in the said conducting circle corresponding to the space existing between two consecutive turns, a connection connecting one of the ends,

of the conducting circle to the other conductor of the radiogoniometry station, and means for connecting to the said circuit a variable number of the turns of the said endless winding.

3. In a system of radiogoniometry comprising an endless Winding, the connection of one of the turns of the said Winding with one ofthe conductors of the radiogoniometry station, a conducting circle extending-above the whole of the said turns, a gap in the said conducting circle corresponding to the space existing between two consecutive turns, a connection connecting one of the ends of the conducting circle to the other conductor of the radiogoniometry station, a'removable rider arranged on the said circle and rubbing on a bare portion of said endless winding.

4:. In a system of ra-diogoniometry com-' the turns of the prising an endless Winding, the connection station, a conducting circle extending above the Whole of the said turns, a gap in the said conducting circle corresponding to the space existing between two consecutive turns, a connection connecting one of the endsof the conducting circle to'the other conductor of the radiogoniometry station, a movable rider arranged on the said circle and rubbing ona'bare portion of the turns of the said endless Winding, and means for cans-- ing the position of the gap ofthe conducting circle to vary relatively to the turns of the endless winding,

5. Ina system for radiogoniometr y comprising an endless Winding, the connection of one of the turnsof the said winding with one of the conductors of thradiogoniometry station, a conducting circle extending above the whole of the said turns, a. gap in the said conducting circle corresponding to the space existing between two consecutive turns, a connection connecting one of the ends of the conducting circle to the other conductor of the radiogoniometi y station, a mov able rider arrangedon the'said circle and rubbing on a bare portion of the turns of the said endless Winding, a contact arranged at one of the ends of the conducting circle for rubbing on the bare portion of the turns of the said endless Winding, and aconnection connecting the end of the circle to one of the conductors of the radiogoniometry station.

In testimony whereof I have signed my name to this specification.

WILLIAM ARTHUR Lorri. 

